Add olive oil to Instant Pot® and select the sauté function. Set to high and once the display reads “hot,” add red onion, poblano peppers, garlic powder, and Italian seasoning.
Season with salt and black pepper, to taste, and cook, stirring continually, until the onions and pepper soften and develop a bit of color, approximately 4-5 minutes.
Transfer veggie mixture to a separate medium bowl. Add ground beef to the Instant Pot and brown for 3-4 minutes, or until no longer pink, stirring occasionally.
Turn the unit off and carefully drain any excess fat from the Instant Pot, keeping the ground beef inside the Instant Pot.
Pour sautéed veggies on top of the browned beef. Add broth, crushed tomatoes, and brown rice. Stir to combine and season with salt and black pepper, as desired.
Add the lid and set the pressure valve to “sealing.”
Select the “Manual” cooking option on the high setting and set cook time to 20 minutes. When done cooking, allow the pressure to release naturally for 10 minutes, and then do a quick release for any remaining pressure by switching the pressure valve to "venting". Be careful - hot steam will come out the hole!
To serve, transfer soup to individual bowls and garnish with fresh chopped parsley, if desired.